I've only got a second, I'm afraid.
Did the PP for the housing include PP to demolish a section of the wall?
1) Inclusion on the RPS means that a structure can't be demolished, altered, extended etc. without PP.
2) This should be done through the local authority.
3) He should have to reinstate it exactly as it was. See the case of Archer's Garage in Dublin (documented on this site- just do a search) for a not-dissimilar example, though in that case the damage was deliberate.
A few sections of the Planning and Development Act 2000 that might be of relevance (taken from the irishstatutebook.ie site- look in Acts of the Oireachtas - Year 2000 - No 30 - Part IV):
57.â€”(1) Notwithstanding section 4(1)(h), the carrying out of works to a protected structure, or a proposed protected structure, shall be exempted development only if those works would not materially affect the character ofâ€”
(a) the structure, or
(b) any element of the structure which contributes to its special architectural, historical, archaeological, artistic, cultural, scientific, social or technical interest.
58.â€”(1) Each owner and each occupier shall, to the extent consistent with the rights and obligations arising out of their respective interests in a protected structure or a proposed protected structure, ensure that the structure, or any element of it which contributes to its special architectural, historical, archaeological, artistic, cultural, scientific, social or technical interest, is not endangered.
(2) The duty imposed by subsection (1) in relation to a proposed protected structure arises at the time the owner or occupier is notified, under section 55 or under Part II, of the proposal to add the structure to the record of protected structures.
(3) Neither of the following shall be considered to be a breach of the duty imposed on each owner and each occupier under this sectionâ€”
(a) development in respect of which permission under section 34 has been granted;
(b) development consisting only of works of a type which, in a declaration issued under section 57(3) to that owner or occupier, a planning authority has declared would not materially affect the character of the protected structure or any element, referred to in subsection (1) of this section, of that structure.
(4) Any person who, without lawful authority, causes damage to a protected structure or a proposed protected structure shall be guilty of an offence.
(5) Without prejudice to any other defence that may be available, it shall be a good defence in any proceedings for an offence under subsection (4) to prove that the damage to the structure resulted from works which wereâ€”
(a) urgently required in order to secure the preservation of the structure or any part of it,
(b) undertaken in good faith solely for the purpose of temporarily safeguarding the structure, and
(c) unlikely to permanently alter the structure or any element of it referred to in subsection (1).
59.â€”(1) Where, in the opinion of the planning authority, it is necessary to do so in order to prevent a protected structure situated within its functional area from becoming or continuing to be endangered, the authority shall serve on each person who is the owner or occupier of the protected structure a noticeâ€”
(a) specifying the works which the planning authority considers necessary in order to prevent the protected structure from becoming or continuing to be endangered, and
(b) requiring the person on whom the notice is being served to carry out those works within a specified period of not less than 8 weeks from the date the notice comes into effect under section 62.
(2) After serving notice under subsection (1) on a person, a planning authority mayâ€”
(a) at its discretion, assist the person in carrying out the works required under the notice, and
(b) provide such assistance in any form it considers appropriate, including advice, financial aid, materials, equipment and the services of the authority's staff.
(3) Any person on whom a notice under subsection (1) has been served may, within 4 weeks from the date of service of the notice, make written representations to the planning authority concerningâ€”
(a) the terms of the notice,
(b) the provision of assistance under subsection (2), and
(c) any other material considerations.
(4) After considering any representations made under subsection (3), the planning authority may confirm, amend or revoke the notice, and shall notify the person who made the representations of its decision.
(5) Particulars of a notice served under this section shall be entered in the register.